Jim,
I agree with the draw back of the thermal bonding. Alternative method is
Ultra sonic bonding. The main advantage of ultrasonic bonding is that,
it is totally prototype, after bonding you will not lost any of your
microfluidic dimension and the bonding is compact. All you have to do to
energy direction just besides your micro channel, no matter how narrow
they are.
Besides that, you can try with

annealing [L.J. Kricka, P. Fortina, N.J. Panaro, P. Wilding, G.
Alonso-Amigo, H. Becker, Lab. Chip 2 (2002) 1.],

lamination [J.S. Rossier, P. Bercier, A. Schwarz, S. Loridant, H.H.
Girault, Langmuir15 (1999) 5173.],

adhesives [F. Dang, S. Shinohara, O. Tabata,Y.Yamaoka, M.Kurokawa,Y.
Shinohara,M. Ishikawa, Y. Baba, Lab. Chip 5 (2005) 472.]

or solvents [R.T. Kelly, T. Pan, A.T. Woolley, Anal. Chem. 77 (2005)
3536.].

Regarding , solvent bonding I am currently working on it for the several
polymeric materials for the last few days. I have able to design a
compact protocol for PS, and currently working on the PMMMA, PC and
PDMA. Unfortunately, for the publication, I cannot supply the protocol
at this moment.
Best Wishes,

Mamun Rashid
PhD Student
Centre for Nano & Microsystems
University of Teesside
TS1 3BA. U.K
www.mamun.info
+44(0)164 234 2428

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Jim
Sent: 01 August 2007 16:24
To: General MEMS discussion
Subject: Re: [mems-talk] PDMS to PMMA/polycarbonate bonding

Mamun,
Appreciate your response first.  I have got the first paper but the
second
one is hardly got.

Basically, the first paper is talking about thermal bonding between PMMA
to
PMMA. I am pretty sure it will do. I actually did that before. I am not
sure
it is feasible to do PDMS to PMMA thermal bonding since the microfluidic
structure will get deformed at PDMS part.  Also, I have baked my
combination
upto 100C, which is very close to PMMA glass temperature, still no
bonding
effect.

Is there any solvent based bonding recipe?
Many thanks,
Jim